2. The sensitization rates to allergic pollen
Allergic sensitization rate for tree pollens has been increased from
year to year. The first pollen observations tended to be moved forward
and increased the duration of pollen seasons. The sensitization to tree
pollens was gradually increased for the last 22 years (Table 2).
Sensitization to oak, hazel, and alder pollens had the highest rate of
increase (0.28% annually), followed by that to birch, willow, and pine
pollens (0.25%, 0.25%, and 0.23%, respectively) (Table 2). Regarding
age distribution changes for the last 22 years, sensitization rate to
pollens was increased in <10 age of years (Age
3~5 years: 8.3%, 6~9 years: 14.4%,
10~12 years: 24.0%, 13~15 years:
25.4%, and 16~18 years: 27.6 at 1998; Age
3~5 years: 10.7%, 6~9 years: 17.7%,
10~12 years: 22.5%, 13~15 years:
23.9%, and 16~18 years: 25.3 at 2019) (Fig. 1).